That damage to ocular tissues may occur by exposure to various wavelengths of the electromagnetic spectrum has long been known. Damage is dependent on the amount of energy absorbed. With development, in recent years, of a wide variety of sources of powerful electromagnetic radiations, some of which are, in addition, coherent (i.e., masers and lasers) the potential for accidental injury to the eye grows. The Principal Investigator and his colleagues propose to evaluate the sequence of morphologic events produced in ocular tissues by such devices in both the visible and invisible portions of the spectrum. Current methods of light and electron microscopy will be applied to these studies. This project consists of two parts: (1) An evaluation of two important regions of the invisible spectrum using (a) an ultraviolet laser to determine effects on cornea, lens, and possibly the retina in short (days, weeks) and medium terms (months to a year) experiments; (b) microwave radiations to determine mainly the effects on the lens in short, medium, and long term (i.e., years) experiments. (2) An evaluation of damage to the primate fovea by coherent visible light using a continuous (CW) laser (Argon). The proposed studies are currently of great clinical importance in the matter of evaluating the potential for accidental injury and determination of standards of safety.